I am placing my 912 motor into my 356C shortly.
I have a 200mm clutch pressure plate and disc I got from Rod Emory.
I also have a 200mm flywheel on the engine rather than the larger 912 flywheel, so good here.
The transmission is good, 741, rebuilt by Eric Wills.
The car is 12 volt.

If the 200 mm flywheel is a 356 version then you can use the original starter motor but it would be advisable to change the solenoid to a 12 volt version otherwise you may mess up the teeth on the ring gear because of the extra force imparted to the starter dog by 12 volts being applied to a 6 volt solenoid.

If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
David Jones #9715

I second Davids advice. I installed the 12volt geared starter from Zim's about a year ago. It fits perfectly. There is no bushing required. I have a stock 65C with 200mm. clutch and flywheel. You will be pleased with this product.